Decorative painting apparatus



June 4, 1968 E. 1.. FABER DECORATIVE PAINTING APPARATUS 2 Sheets-Sheet 1 Filed April 15. 1966 l I l I l I L L INVENTOR. .ELMER L. FABBR.

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June 4, 1968 E. L. FABER 3,386,414

DECORAT IVE PAINTING APPARATUS Filed April 13, 1966 2 Sheets-Sheet 2 I N VENTOR.

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United States Patent O 3,386,414 DECORATIVE PAINTING APPARATUS Elmer L. Faber, Toledo, Ohio, assignor to Deco Tools, Inc., Toledo, Ohio, a corporation of Ohio Filed Apr. 13, 1966, Ser. No. 542,318 Claims. (Cl. 118323) ABSTRACT OF THE DISCLOSURE A decorative painting apparatus for reciprocating spray guns along a rectilinear path. The apparatus having a driven member which supports a spray gun post. The post mounts one or more spray guns in painting relationship to a workholder. Opposed guide members are mounted parallel to the path and slide members, which are connected to the driven member, reciprocate along the opposed guide members. A motor driven driver is connected to the driven member and reciprocates the driven member, the slide members, the post, and the spray guns. A counterweight is positioned on the driver to reduce spray gun inertia dwell at the ends of each stroke and the apparatus includes means for adjusting the length of the stroke.

This invention relates to decorative painting apparatus and, more particularly, to an improved decorative painting apparatus for reciprocating at least one spray gun along a predetermined rectilinear path.

In the decorative painting art, a workpiece to be coated, for example, an automotive dashboard panel, is placed in a workholder. A mask having accurately formed openings is placed in overlying relationship to the workpiece surface which is to be painted. The openings in the mask define the areas of the workpiece surface which are to be painted. Paint is supplied to the workpiece surface through a spray gun, for example, an atomizing air type spray gun.

It has been found that hand-held spray guns and prior art decorative painting mechanisms have been generally unsatisfactory in many decorative painting operations. It is important that the paint be applied evenly to the workpiece surface. In mass production operations it is also important that the paint be applied to the selected areas of the workpiece, with as little paint as possible contacting the mask. If too much of the paint is oversprayed onto the mask, it results in both paint loss and also excessive mat cleaning.

Prior art decorative painting mechanisms had a tendency to dwell at the end of a painting stroke when the spray gun was reciprocated along a predetermined path. This dwell resulted in a buildup of paint at the ends of the workpiece. Another objectionable feature of prior art decorative painting apparatus was the failure of adequate guiding means to direct the guns along the predetermined path. This resulted in both an excessive wasting of paint and objectionable vibration of the spray guns.

It is the primary object of the present invention to provide an improved decorative painting apparatus.

It is another object of the present invention to provide a decorative painting apparatus which has means for guiding a spray gun along a predetermined path.

It is a further object of the present invention to provide a decorative painting apparatus which reduces spray gun inertia dwell at the ends of each stroke.

It is a still further object of the present invention to provide a decorative painting apparatus which includes means for adjusting both the rate of travel and the stroke of a reciprocating spray gun.

Further objects of this invention will become apparent from the following specification and drawings in which:

3,386,414 Patented June 4, 1968 FIG. 1 is a top plan view of a decorative painting apparatus, according to the instant invention;

FIG. 2 is a vertical sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a fragmentary plan view, with parts shown in section, taken along the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary elevation view, with parts broken away, taken along the line 44 of FIG. 3; and

FIG. 5 is a perspective view of a portion of a driver assembly, according to the present invention.

Briefly, the invention relates to decorative painting apparatus for reciprocating at least one spray gun along a predetermined rectilinear path. The decorative painting apparatus comprises a longitudinally extending post having at least one spray gun mounted thereon. Driven means are provided for supporting the post and the apparatus includes guide means for guiding the movement of the post along the predetermined path. A driver is operatively connected to the driven means and is effective to reciprocate the driven means. The driver includes counter force means effective to reduce spray gun inertia dwell at the ends of each stroke. Motor means are operatively connected to the driver.

Referring to the drawings, a decorative painting apparatus embodying the instant invention is generally indicated by the reference number 11). The decorative painting apparatus 10, in this embodiment, includes a worktable 11 having a top 12 and a bottom 13. The worktable 11 is supported by legs 14 and the entire decorative painting apparatus 10 normally is enclosed "by a housing (not shown).

The worktable 11 has a longitudinal slot 15 extending therethrough and a workholder 16 is mounted at one end of the top 12. The workholder 16 may be positioned in various locations with respect to the worktable 11 and still be within the scope of the present invention. For example, the workholder 16 may be positioned above the top 12 of the worktable 11 (not shown). In this event, the Workpiece lies in a horizontal plane which is parallel to the top 12 as opposed to the vertical position shown in FIG. 2.

Referring to FIGS. 1 and 2, the workpiece 17 is positioned within the workholder 16 and has a surface 18 which is to be painted. A mask 19 is placed over the surface 18. Only a selected portion of the surface 18, which is defined by the mask 19, is painted.

Referring to FIG. 2, an electrical motor 22 having an output shaft 23 is positioned beneath the worktable 11. The motor 22 is supported by an adjustable motor base 24 which is mounted to the bottom 13 of the worktable 11 by a plurality of bolts 25.

A rectangularly shaped platform 26 also depends beneat-h the worktable 11 and is supported by a plurality of columns 27 which are fastened to the worktable 11.

A speed reducer mechanism 28 having an input shaft 29 is mounted on the platform 26. A step pulley 30 is keyed to the output shaft 23 of the motor 22 and a step pulley 31 is keyed to the input shaft 29 of the speed reducer mechanism 28. A belt 32 extends between the step pulleys 30 and 31. To adjust the tension of the belt 32 a handle 33 of the adjustable motor base 24 is turned.

The speed reducer mechanism 28 has a rotatable output shaft 34 which is operatively connected to the motor 22. A driver 35 (see FIG. 5) having a control opening 36 is keyed to the output shaft 34 of the speed reducer mechanism 28. The central opening 36 of the driver 35 receives the shaft 34 and the driver 35 is secured to the shaft 3.4.

In the present embodiment, the driver 35 has an outwardly ext-ending arm 37. The arm 37 defines a plurality of longitudinally spaced engager openings 38 which extend through the arm 37. A cam engager 39 is removably mounted in one of the engager openings 38, for example, in the outermost opening 31%. The cam engager 39 may be positioned within various ones by the engager openings 38 to vary the stroke of the spray guns, as will be explained in detail below. In the preferred embodiment, the cam engager 39 includes an upper roller 40 which is mounted for rotation around a vertical axis.

The driver 35 includes an integral counterweight 41 which is diametrically opposed to the outwardly extending arm 37 with respect to the central opening 36. The counterweight 41 acts as a counterforce means which is effective to reduce spray gun inertia dwell at the ends of each stroke during the operation of the decorative painting apparatus 18.

Referring to FIGS. 1, 3, and 4, opposed brackets 45 and 46 depend downwardly from and are connected to the bottom 14 of the worktable 11. In the drawings, a predetermined rectilinear path is designated by the reference number 47. In this embodiment the predetermined path 47 coincides with the longitudinal centerline of the worktable slot 15. Opposed horizontal guide bars 48 and 49 are mounted beneath the worktable 11 by the brackets 45 and 46. The guide bars 48 and 4 are parallel to the predetermined path 47. The guide bar 48 is mounted on one side of the path 47 and the guide bar 49 is mounted in opposed relationship on the opposite side of the path 47.

A slide block 59 having a longitudinal bore 51 is mounted for reciprocation on the guide bar 48. Bearings 52 (see FIG. 3) are provided adjacent the ends of the bore 51. Similarly, a slide block 53 having a longitudinal bore 54 is mounted for reciprocation on the guide bar 49. Bearings 55 are provided at opposed ends of the bore 54.

A drive bar 56 which extends generally transversely to the predetermined path 47 is fixedly mounted to the opposed slide blocks 50 and 53 for movement therewith. The drive bar 56 has a longitudinal cam slot 57 which in the present embodiment extends through the bar 56. The cam slot 57 receives the roller 46 of the cam engager 39 which is mounted on the arm 37 of the driver 35.

A mounting block 60 is fixedly connected to the upper surface of the drive bar 56 and in turn mounts a longitudinally extending spray gun post 61. The post 61 extends upwardly through the worktable slot 15. Referring to FIG. 2, a spray gun 62 is mounted on the post 61 in spraying relationship with the workpiece 17. If desired, one or more spray guns, for example, a spray gun 62a may be mounted on the post 61 to spray upwardly if the workpiece to be painted is in the alternative position above the worktable 11.

In a typical decorative painting operation a workpiece, for example, the workpiece 17 is placed in the workholder 16 and the decorative paintin mask 19 is placed over the workpiece surface 18. The stroke required is measured and the cam engager 39 is mounted in a respective one of the engager openings 38 in the arm 37 of the driver 35. In the present embodiment, the stroke will equal two times the distance from the vertical centerline of the cam engager 39 to the vertical centerline of the output shaft 34 of the speed reducer mechanism 28.

The belt 32 is then positioned on the step pulleys 30 and 31 to give the desired speed to the input shaft 29 of the speed reducer mechanism 28. Any adjustment to the tension of the belt 32 is made by turning the handle 33 of the adjustable motor base 24.

The motor 22 is actuated, driving the rotatable shaft 34 of the speed reducer mechanism 28. The cam engager 39, which is mounted on the driver arm 37, is positioned within the cam slot 57 of the drive bar 56 and as the driver 35 is rotated the cam engager 39 transfers force to the drive bar 56.

The drive bar 56 is accurately guided in its movement by the guide bars 48 and 49 on which slide blocks 50 and 53 are reciprocating. As the drive bar 56 reaches the ends of a stroke, such positions being indicated in FIG. 3 by the reference numbers 56a and 56%, there is a tendency for the apparatus to hesitate during the change of direction of the spray guns. This tendency has been termed spray gun inertia dwell and such dwell results in faulty decorative painting because of a paint buildup on the workpiece.

In the present invention, 'spray gun inertia dwell is reduced by counterforce means which in the present embodiment comprises the counterweight 41 on the driver 35. The kinetic energy of the rotating counterweight 41 provides a counterforce which tends to overcome the inertia forces of the driver and its associated components.

The slide blocks and S3 and the guide bars 48 and 49 insure that the post 61 moves along the predetermined path 47 with very little sidcward motion or vibration.

The present invention provides an improved decoralive painting apparatus which eliminates many of the disadvantages of prior art devices.

While the present invention has been disclosed in connection with a specific arrangement and disposition of the parts, it should be expressly understood that numerous modifications and changes may be made without departing from the scope of the appended claims.

I claim:

1. Decorative painting apparatus for reciprocating at least one spray gun along a predetermined rectilinear path of a predetermined stroke length, comprising, in combination, a longitudinally extending post having at least one spray gun mounted thereon, driven means for supporting said post, guide means for guiding the movement of said post along such predetermined path, said guide means including opposed guide members mounted parallel to such predetermined path, slide members mounted for reciprocation on each of said guide members, said driven means being operatively connected to said slide members, a driver mounted on a predetermined axis of rotation operatively connected to said driven means and effective to reciprocate said driven means and said post along such predetermined path for a given stroke, said driver including counterforce means effective to reduce spray gun inertia dwell at the ends of each stroke, said counterforce means including a counterweight on said driver spaced from such axis of rotation, means for adjusting the stroke length of said spray gun, and motor means operatively connected to said driver.

2. Decorative painting apparatus according to claim 1, wherein said driven means comprises means for mounting said post, and a drive bar extending generally transversely to such predetermined path, said drive bar defining in its surface a cam slot.

3. Decorative painting apparatus, according to claim 2, wherein said guide members comprise opposed guide bars mounted adjacent to such predetermined path on opposed sides thereof, said guide bars being mounted parallel to such predetermined path, and wherein said slide member comprises a slide block mounted for reciprocation on each of said guide bars, and wherein said drive bar is fixedly mounted to opposed ones of said slide blocks for movement therewith.

4. Decorative painting apparatus according to claim 2, wherein said driver is mounted on a rotatable shaft, said shaft being operatively connected to said motor means, said driver including an outwardly extending arm, and a cam engager mounted on said arm, said cam engager positioned for movement within said drive bar cam slot.

5. Decorative painting apparatus according to claim 4, wherein said counterweight is diametrically opposed to said cam engager.

6. Decorative painting apparatus according to claim 4, wherein said adjusting means is located on said outwardly extending arm and wherein the position of said cam engager with respect to said rotatable shaft can be adjusted, whereby the stroke of said post is variable.

7. Decorative painting apparatus according to claim 1, including a work table having a longitudinal slot defined therein, said post extending through such work table slot and Workholding means for holding a workpiece in spaced relationship to said spray gun.

8. Decorative painting apparatus according to claim 7, wherein said guide members comprise opposed guide bars mounted beneath said work table on opposed sides of such work table slot, said guide bars being parallel to such predetermined path, and wherein said slide member comprises a slide block mounted for reciprocation on each of said guide bars, wherein said driven means comprises means for mounting said post and a drive bar mounted to opposed ones of said slide blocks for movement therewith, said drive bar defining a cam slot, and wherein said driver is mounted on a rotatable shaft, said shaft being operatively connected to said motor means, said driver having an outwardly extending arm and a cam engager mounted on said arm, said cam engager being positioned for movement within said drive bar cam slot.

9. Decorative painting apparatus, according to claim 8, wherein said counterforce means comprises an integral counterweight which is located on said arm in opposed relationship to said cam engager.

10. Decorative painting apparatus, according to claim 9, including means for adjusting the stroke of said post, said adjusting means comprising a plurality of engager openings defined in said arm, said cam engager being removably mounted in one of such engager openings.

References Cited UNITED STATES PATENTS 2,559,225 7/1951 Ransburg l18323 X 2,841,993 7/1958 Kaufmann 74-50 2,988,924 6/1961 Cooley 74-50 3,052,212 9/1962 MacArthur et a1. 118323 X 2,728,238 12/1955 Paasche 118-323 X CHARLES A. WILLMUTH, Primary Examiner. JOHN P. MCINTOSH, Assistant Examiner. 

